194 Pecan-Growing 



tissues. The dead brown tissues are surrounded by a seem- 

 ingly normal green husk. However, as the disease progresses, 

 sunken glossy black spots and blotches appear on the outside 

 of the husks and the nuts soon fall to the ground. 



Little is known of this disease, and so far it has not caused 

 very serious trouble. Often when there are three or four 

 nuts in one cluster, apparently the weaker ones succumb to 

 the disease, indicating what some have termed a self-pruning 

 process. 



WOOD-ROTTING FUNGI 



Wounds arising from mechanical injuries of pecan trees, 

 as pruning, hail, windstorms, and the like, make possible 

 points of entrance of wood-rotting fungi. Unless the wounds 

 are given some protective covering during the healing-over 

 process, serious injuries are likely to result. Painting the 

 wounds with coal tar is one of the simplest methods of pro- 

 tection. It may be necessary to paint large wounds twice or 

 three times before they finally heal. "Wounds already invaded 

 by the wood-rotting fungi should be cut out down to the 

 sound wood before treating. In this case a coat of creosote 

 followed by a coat of coal tar is advisable. Large cavities, 

 after the decayed wood has been chiseled out and the walls 

 have been disinfected, may be filled with concrete, a method 

 practiced in modern tree-surgery. 



TIP-BURN AND WINTER-INJURY 



Tip-burn of pecans is indicated by the tips and the margin 

 of the leaflets becoming brown in hot dry periods. If the 

 weather conditions are extreme the leaves may die. Tip-burn 

 is thought to be due to excessive evaporation. It is not 

 considered a very serious trouble. 



